Remove unused python imports
Fix generation of unicode strings in OsmSax
Add tests for OsmSaxReader
Fix OsmSaxAlea reader

There were case where the code didn't converge to the wanted element,
especially if this element had a lot of nodes or members.

Gzip files were also incorrectly handled, as b_max was set to the size of the
compressed file instead of the uncompressed file.
Add tests for OsmSaxAlea
Add tests for OsmPbf
Switch to dmetaphone() instead of fn_soundex2() in non-french language
Report an error when country lock cannot be taken
Add tests for plugins
Fix unicode encoding in plugin TagFix_MultipleTag_FR